HRTEM study of ⟨011⟩ type II twin in NiTi shape memory alloy

The present authors have recently reported the atomic structure of ⟨011⟩ type II twin in NiTi shape memory alloy. In the present research, the atomic structure of ⟨011⟩ type II twin is further studied by using HRTEM in combination with atomic image simulation. Based on the model of type II twin constructed, the simulated HRTEM images are in good agreement with the experimental observations. The results provide further evidence that the two twinned martensite variants are interfaced by segment of (11 ) plane. The overall type II twin boundary is composed of (11 ) segments that are connected by steps in atomic scale.